The Role of Inert Gas Systems in Semiconductor Fabrication

The unique properties of inert gases have enabled the semiconductor industry to maintain cleanliness and productivity in their manufacturing process. The demand for these gases is so huge that the market is estimated to be worth about 6.1billion dollars by 2028, despite the semiconductor shortage during the COVID-19 pandemic.

The gas delivery system acts as the mediator between the gas source and the production process. This is where manufacturers should be mindful of preventing leaks and contamination. Custom inert gas systems specific to your process condition will ensure a precision supply of these gases to your fabrication unit. Let us explore the multiple roles of inert gas systems in ensuring the productivity and reliability of your semiconductor fabrication process.

The Different Semiconductor Grade Gases

To establish the standard of what to use and when, the gases used for manufacturing purposes have been specified into three grades, which are:

1. Industrial grade
2. Labortory grade
3. Ultra-high purity grade

Semiconductor-grade gases are high-purity gases used for purging or aiding in different stages of fabrication. The inert gas, in particular, plays a crucial role in different stages of semiconductor fabrication. These include standard inert monatomic gases like argon or helium, though diatomic gases like nitrogen can also be used for blanketing or to provide an inert condition. The table below indicates the types of gases used and the processes in which they are used.

The chemically inert gases help eliminate existing and potential impurities from the different fabrication steps. This inert nature needs to be preserved throughout the process—from the source to the point of use. So, it is crucial for manufacturers to invest in a high-quality inert gas system. 

The Role of An Efficient Inert Gas System

Before designing or selecting the right inert gas system, it is beneficial to explore the few challenges that fabrication facilities face. These are:

1. Leaks: Leaks lead to the pressure losses, cause contamination, and increase operational/ maintenance costs.
2. Safety: Some gases are precursors for chemical warfare. It's about more than just frostbite and burn hazards—it can be life or death. 
3. Downtime: Frequent maintenance or changeovers leads to unplanned downtime, compromising productivity. 

A reliable inert gas system must be robust, safe, and easy to troubleshoot. At each stage of the semiconductor fabrication process, the specialized inert gas system should operate as per the specifications (i.e., temperature, pressure, and gas discharge rate) to achieve the desired reaction. Here are a few things to keep in mind when custom-designing your inert gas delivery system.

1. Backflow Prevention

Manufacturers should be mindful of preventing backflow when dealing with inert gas. Backflow can have serious implications, not just for the impending procedure down the line but also for the safety of the gas delivery system. For instance, if oxygen backs into the system with nitrogen blanketing, the result can be hazardous. Check valves can be used to control backflow for high-purity applications. 

2. Temperature and Pressure Control

The T&P control of inert gases directly correlates to the consistency of fabrication in processing chambers. Control and relief valves and pressure regulators can work in unison to achieve the pressure required at the inlet and outlet. Insulation can be used to prevent cryogenic heat transfer.  

3. Controlled Mixing

In many cases, the production process may require a mixture of inert or specialty gases. For instance, a diborane and hydrogen mixture may be required during doping to control decomposition. With the use of gas manifolds, these gases can be mixed at the point of use.

Need Help Installing a Reliable Inert Gas System?

The quality of an efficient inert gas system is its ability to provide controlled flow while ensuring there are no unwanted mixing, backflow, or leaks. This can be accomplished by using high-quality components such as valves, manifolds, and pressure regulators—provided by Swagelok. These components can help you fabricate a gas delivery system that enables an uninterrupted supply of inert gas to the processing unit.

Swagelok also provides consultation services for Northern California facilities seeking system optimization advice or help identifying the right solution for the efficient run of your delivery system. Swagelok is your local fluid system expert and your answer to unlocking efficiency and productivity in your semiconductor fabrication process.

To find out more about how Swagelok Northern California can support your need for the design and installation of an inert gas system,contact our team today by calling 510-933-6200.

About Morgan Zealear | Product Engineer, Assembly Services

Morgan holds a Bachelor of Science in Mechanical Engineering from University of California at Santa Barbara. He is certified in Section IX, Grab Sample Panel Configuration and Mechanical Efficiency Program Specification (API 682), and he is well versed in B31.3 Process Piping Code. Before joining Swagelok Northern, he was a manufacturing engineer at Sierra Instruments, primarily focused on capillary thermal meters for the semiconductor industry (ASML).